Wind turbines normally comprise one or more energy generating units, each energy generating unit comprising a rotor comprising a hub carrying one or more wind turbine blades. The wind acts on the wind turbine blades, thereby causing the hub to rotate. The rotational movements of the hub are transferred to a generator, either via a gear arrangement or directly, in the case that the wind turbine is of a so-called direct drive type. In the generator, electrical energy is generated, which may be supplied to a power grid.
Some wind turbines are provided with two or more energy generating units in order to increase the total power produced by the wind turbine, without having to provide the wind turbine with one very large, and therefore heavy, energy generating unit. Such wind turbines are sometimes referred to as ‘multirotor wind turbines’.
In multirotor wind turbines the energy generating units may be carried by one or more load carrying structures which are, in turn, connected to a tower structure. Thereby at least some of the energy generating units are not mounted directly on the tower structure, and they may be positioned at a large distance away from the tower structure.
GB 2 443 886 A discloses a multirotor wind turbine comprising a tower and at least two arms projecting outwards there from. A rotor is attached to an end of each arm. The rotors can be hoisted to or lowered from the arms along a substantially vertical direction.